R- tm，stringr r，perl regex中的关系-三元组提取

Question

在从文本中学习本体的情况下，假设我有两个概念，并且我对它们之间的关系感兴趣：

class <- c(animal.class, dog.class)
individual <- "Snoopy"

animal.class <- c("animal", "animals")
dog.class <- c("dog", "dogs")

sentence1 <- "Snoopy is an animal."
sentence2 <- "Snoopy is a dog."

如何提取与R的语言上下文和语义关系，以便我可以收集数据帧，而不需要之前定义的上下文/关系("is a(n)")。

data.frame(CLASS1="animal",CLASS2="Snoopy",context="CLASS2 is an CLASS1")
data.frame(CLASS1="dog",CLASS2="Snoopy",context="CLASS2 is a CLASS1")

用其他工具很容易提取这种东西，比如有限状态转换器，但我想留在R中，目前我在R中找不到任何类似的东西。

我设想了一些使用perl regex以及tm和stringr包的解决方案...它们足够了吗？

Answer 1

我不太确定你在找什么。这就是我认为你要做的事情：

sentences <- c(
    "Snoopy is an animal.",
    "Snoopy is a dog.",
    "Snoopy likes chocolate!",
    "Goofy is a dog"
)

if (!require("pacman")) install.packages("pacman")
pacman::p_load(qdapRegex, dplyr, tidyr)

(out <- rm_default(sentences, pattern = S("@around_", 1, "is a(n*)", 1), extract=TRUE) %>%
    unlist %>%
    sub("\\s+", "<SPLIT>", .) %>%
    data_frame(new = .)  %>% 
    na.omit %>%
    separate(new, c("CLASS2", "context", "CLASS1"), sep = "(<SPLIT>)|( (?=[^ ]+$))") %>%
    mutate(context = sprintf("CLASS 2 %s CLASS 1", context)) %>%
    select(c(1, 3, 2))) 

##   CLASS2 CLASS1               context
## 1 Snoopy animal CLASS 2 is an CLASS 1
## 2 Snoopy    dog  CLASS 2 is a CLASS 1
## 3  Goofy    dog  CLASS 2 is a CLASS 1

然后，要提取各种CLASSes的特定实例，请在管道末尾使用filter：

out %>%
    filter(grepl("[Ss]noopy", CLASS2))

##   CLASS2 CLASS1               context
## 1 Snoopy animal CLASS 2 is an CLASS 1
## 2 Snoopy    dog  CLASS 2 is a CLASS 1

out %>%
    filter(grepl("[Dd]og", CLASS1))

##   CLASS2 CLASS1              context
## 1 Snoopy    dog CLASS 2 is a CLASS 1
## 2  Goofy    dog CLASS 2 is a CLASS 1